Leaving aside all the references to the “non-aggression pact of Gíjon”, and the endless discussion of final group G permutations that might see the US advance, there’s one stat that may set the tone for the USA’s encounter with Germany.

10-3.

That’s the number of goals conceded set against the number of goals scored in this World Cup, by teams that had played their previous games in Manaus. And as Jurgen Klinsmann stressed rather emphatically in the immediate wake of the Portugal game, and then in rather more poised fashion the next day, you’d have to imagine it’s advantage Germany and Ghana, physically at least, going into the final group games.

Now, of those post-Manaus conceded goals, four were against an abject Cameroon team facing Brazil, but more worrying has been the second half performances by those teams. Italy and England both looked like they were sleepwalking in their second group games, and lost them; Croatia caved in late to Mexico.

So for all that one can look at all the Group G teams’ performances so far and consider the proactive possibilities of Fabian Johnson getting in behind the German full-backs, it’ll be the more prosaic qualities of stamina and concentration that will be examined, should the group still be up in the air going into the last quarter of the game.

And those are the qualities (or at least the combination of those qualities) where USA were found just lacking against Portugal. Whether it was a fresh-legged DeAndre Yedlin trying to trap the ball in a corner instead of accepting a throw, a tired Michael Bradley being muscled off the ball, a weary Geoff Cameron switching off and failing to cover his runner on the equalizer, or just the general sight of a handful of defenders ball-watching at the death, there were any number of injury time lessons the US were served with, on top of the physical debilitation of playing their attacking game in the heat and humidity of Manaus.

So what lessons do they take into the German game? Well, they learned a little more about trusting their subs. Wondolowski didn’t have a lot to do but tried to be smart in doing it. Yedlin, minor late aberration aside, was a confident and productive wide attacking option as much as he was once a fourth choice right-back. The question though is how much Klinsmann will be prepared to rotate his team given the success of the last game — we haven’t seen young Julian Green yet for example, and Brad Davis’s tenacity and set piece skill could be a midfield option at some stage.

This may be the moment we see just how much Klinsmann trusts every member of his squad. If they go out without Green in particular seeing the field, expect the same sort of inquest that surrounded the unused Theo Walcott in the 2006 England squad.

But it’s in central defense Klinsmann has a headache. The kindest thing you could say about Geoff Cameron on Portugal’s first goal was “these things happen” (as opposed to, “what’s an international defender doing defending on his heels in the box?”). And while he composed himself for the remainder of the game, Cameron’s anticipation was at least one of a series of weak links in the chain, during Portugal’s final game-leveling attack.

I’m imagining Cameron will continue to lead the defense despite his degree of culpability on both Portugal goals. That’s largely because his obvious replacement, Omar Gonzalez, tasked with the simple task of helping tidy up in the box with the US defending a lead, was once again awol, as he had been when given the same task as a late sub against Nigeria. Supersub John Brooks can do a job again if needed, but a clear-sighted assessment of him has to include his lack of concentration on Ghana’s goal as well as the header he scored at the other end moments later. He needs a more reactive defender to partner alongside him. For the longest time in qualifying that was assumed to be Gonzalez. Right now, it’s Cameron.

With Jozy Altidore still out with his hamstring strain, Dempsey will probably start up front alone again, having led the line smartly on Sunday. He was able to perform well in what’s not his ideal position partly because the USA were aggressive in their movement behind him. Pinned back, as they were against Ghana, they’re a team to watch through closed fingers. Springing forward, their natural posture makes more sense, and generally looks a decent antidote to their defensive frailties.

Portugal’s early goal ironically liberated the US and also revealed what damage they can do when they attack full backs – which brings us back to Germany. If there’s a weakness for Germany, it might be balls behind their wide defenders. On that note, given all the subplots and back stories around Klinsmann’s history with the German team, it’s intriguing to note that one of his most vehement critics, Philipp Lahm, is likely to revert to his natural full-back position, with Bastian Schweinsteiger coming in to midfield.

But regardless of who’s at full-back for Germany, consider the positioning of Fabian Johnson as a kind of barometer. When USA are overloading a flank it’s because he’s getting forward to provide the extra man. If he's cropping up more in his own half, the USA may be trying to sit on a favorable scoreline.

Attack may be USA’s best form of defense, but Klinsmann faces a number of big decisions about how he’d like to play – and how he’s able to play. The extent to which Klinsmann interferes with a successful but possibly fatally weary starting line up will be a big clue. His comments suggest he’d like to trust them to complete the job, but it seems more a case of when, and not if, the exertions of Manaus take their toll. Yet again in this World Cup, it’s difficult to see any good outcome for the USA in this game without the most judicious use of second-half subs.